Summary

Based on CT arthrography analysis at 6 months, failure rate of meniscal repair was significantly higher on the medial side and in case of compartment overload by lower limb malalignment (HKA at > 5 degrees).

Abstract

Background

Identification of predictive factors for failure of repair of vertical tears would help in the decision as whether to repair or resect the injured meniscus. An analysis at the 6 to 12 months timeline is appropriate since previous studies have shown that meniscal repair failure occurs early in the postoperative period.

Purpose

To evaluate predictors for the radiographic and clinical outcomes after meniscal repair of longitudinal vertical tears.
Study design: prospective cohort study; level of evidence, 2.

Methods

single center study. Between 2017 and 2020, all patients receiving meniscal suture for longitudinal vertical tears with or without displacement as a bucket-handle (BHMT) were eligible (n=104). Patients over 50 and under 16 years old, with tears in the white/white zone and revisions meniscal repair were excluded (n=36). Meniscus repair was performed in a full-thickness vertical pattern, with an outside-in approach in all cases. The primary outcome was an assessment of meniscal healing by CT arthrography (CTA) at 6 months, analyzed by an independent observer using Henning’s criteria. KOOS and IKDC scores were collected as a secondary outcome at minimum of 12 months. Hypothesized determinants were age, gender, smoking, simultaneous ACL reconstruction ACLR), varus/valgus malalignment, early osteoarthritic changes (Outerbridge grade II or above), laterality, meniscus zone (red-red vs. red-white), meniscal tear extension and delay before surgery. Multivariable logistic regression was used to determine the odds ratio of each factors for primary and secondary outcomes.

Results

78 consecutive patients were included. Loss to follow up; none at the 6 months CTA, 6% at the 12 months evaluation (5/78). Sex ratio 3, age 29±8.7 years, BMI 24.5±4.8 Kg/m2, active smoking 33%, early OA in 37 %. Medial meniscus (77%) more frequently affected. Compartment overload was defined as valgus/varus malalignment >5° and observed in 14%. ACLR performed simultaneously in 55%. Most tears (53%) affected all segments (BHMT), while 19% were limited to the posterior horn. 42% were localized the red-white zone. At 6 months CTA, failure of repair was observed in 13 % and affected the posterior and middle segment only. Healing was completely achieved in 40%, while incomplete in 47%. Determinants for failures were compartment overload (OR: 3.2; p=0.08) and medial side (OR: 2.5; p=0.08). Compartment overload was also associated with lower KOOS symptoms (OR: 0.35; p=0.022), pain (OR: 0.28; p=0.02), and QOL (OR: 0.44; p=0.05) subscales. Aging was associated with lower KOOS pain (OR: 0.73; p=0.04) and sports (OR: 0.65; p=0.011) subscales, and lower IKDC (OR: 0.83; p=0.04). Medial side was associated with lower KOOS QOL (OR: 0.55; p=0.02).

Conclusion

based on 6 months postoperative CTA, compartment overload by lower limb malalignment > 5° and medial sided lesions are associated with a 3.2 and 2.5-fold increase in meniscal repair failure, respectively. These determinants were also associated lower KOOS subscales at 12 months.